This invention relates to a wheeled carriage for supporting a patient in a substantially horizontal position and, more particularly, to a control mechanism for facilitating control of the raising and lowering feature of onboard hydraulic jacks and to a further control mechanism for controlling the brakes which engage the wheels supporting the wheeled carriage.
Wheeled carriages for supporting a patient in a substantially horizontal position are well known in the art and a representative example of an early version of such a device is illustrated in Dr. Homer H. Stryker""s U.S. Pat. No. 3,304,116, reference to which is incorporated herein. Other of such wheeled carriages are disclosed in U.S. Pat. Nos. 6,230,343 and 6,264,006, both of which are presently owned by the Assignee of record for this invention. Reference to these latter two patents is also to be incorporated herein.
During the assembly of wheeled carriages, strict control over tolerances is always a requirement. This is especially true in mechanisms which are to facilitate the simultaneous raising function of both of the hydraulic jacks onboard the wheeled carriage. In order to effect a simultaneous raising of the hydraulic jacks, and thereby the patient supporting surface, it is essential that the stroke applied to the pumps is the same in order to maintain the patient supporting surface level. Accordingly, a structure which will facilitate the simultaneous raising of the hydraulic jacks and assuring that the stroke applied to each of the hydraulic jacks is the same is highly desired.
It is also essential that there be provided a control for facilitating a lowering of the hydraulic jacks independently of one another, as well as simultaneously. U.S. Pat. No. 6,230,343, mentioned above, provides one type of mechanism for facilitating these tasks. However, it is essential that each of the valves on the hydraulic jacks that controls the lowering function be activated to the same extent during a simultaneous lowering in order to maintain the patient supporting surface horizontal. Thus, a control mechanism for facilitating a lowering of the hydraulic jacks, either independently as well as simultaneously, and which facilitates easy adjustment to compensate for variations and tolerance is highly desirable.
It is also essential that the wheeled carriage be provided with a brake mechanism and U.S. Pat. No. 6,264,006, mentioned above, provides one form of braking mechanism. To simplify the construction of the brake mechanism and thereby effect a reduction in manufacturing expense is always a goal of every improvement. The brake mechanism disclosed herein is no exception.
The objects and purposes of the invention are met by providing an elongate base for a patient supporting platform or surface. The elongate base includes a frame having first and second hydraulic jacks mounted at spaced apart locations and adjacent opposite ends of the frame. Each of the first and second hydraulic jacks are configured to connect to the patient supporting platform for effecting a lifting and lowering of the patient supporting platform relative to the frame. The first and second hydraulic jacks each have a reciprocal input mechanism for effecting, when reciprocated, a lifting of the respective end of the patient supporting platform. Each reciprocal input mechanism has a first part of a two part releasable connection thereon. A manually operable member is mounted on the frame and enables the manually operable member to reciprocate relative to the frame. A linkage member is provided and has a pair of longitudinally spaced second parts thereon, each second part being releasably connected to a respective one of the first parts to effect a connecting of the manually operable member to each of the reciprocal input mechanisms. The linkage is configured to convert the reciprocal movement of the manually operable member to a reciprocal movement of the linkage member to effect a simultaneous lifting of the patient supporting platform in response to the reciprocal movement of the linkage member.
The objects and purposes of the invention are also met by providing on the elongate base set forth above another additional input mechanism on each of the first and second hydraulic jacks for effecting, when reciprocated, a lowering of the patient supporting platform. The additional reciprocal input mechanisms each have a first part of a two part releasable connection thereon, while an additional manually operable member releasably connects through link members to effect a lowering of each hydraulic jack and, consequently, both ends of the patient supporting platform in response to the reciprocal movement of the link members.
The objects and purposes of the invention are additionally met by providing a wheeled carriage for supporting a patient in a substantially horizontal position and a brake mechanism for simultaneously braking each of the castered wheels supporting the wheeled carriage. The brake mechanism includes a pair of elongate bars oriented at opposite ends of the wheeled carriage and which extend transversely of a longitudinal axis of the wheeled carriage. Adjacent opposite ends of each elongate bar there is provided a wheel engaging member. The elongate bar is elastically yieldable and a cam mechanism is provided for effecting a flex of the elongate bar as the wheel engaging members engage the wheels. Upon release of the brake, springs are provided to return the elongate bar to its original unbraked position.